1. Field of the Invention
The present invention relates generally to a partial structure of radiator fan, and more particularly to an innovative one which has a rotor assembly structure.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
The radiator fan is structurally designed to comprise generally a baseplate, a stator assembly and a blade rotor assembly. Currently, there is a growing trend wherein compact radiator fans are developed in tune with thin-profile electronic computer products.
However, some problems are often encountered during design and improvement of the radiator fan, such as: compactness, structural strength and operating stability. The present invention is particularly intended for improving the structure of conventional radiator fan's rotor assembly to realize desired compactness. For instance, as illustrated in ROC's patent No.: M264562 “radiator fan”, the blade rotor assembly disclosed in FIG. 2 is of a typical structure, and its hub is made of plastics. A metal axle is located at the center of the top wall of the hub and protruded downwards, allowing for insertion into the bearing block of the stator assembly. However, it is found during actual applications that, due to the very small diameter of the metal axle (only about 1 mm), the mating area of the metal axle and the hub's top wall is extremely small, leading to difficult matching and poorer locating stability of the metal axle. For this reason, the hub's top wall has to be partially thickened for mating of the metal axle (e.g. disclosed in FIG. 2 in aforementioned M264562). In such case, the increased thickness of hub wall becomes a barrier to the compactness design of the radiator fan.
Referring also to FIG. 3 of patent No. M264562, the hub of the blade rotor assembly is made of plastics, and a plastic sleeve is protruded vertically downwards from the center of the hub's top wall, allowing to accommodate an oil bearing. However, it is found during actual applications that, said hub's top wall must be thick enough (over 1 mm) to guarantee the supporting strength and perpendicularity of the plastic sleeve. Then, a thin-profile hub wall cannot be realized, thus hindering the compactness design of the radiator fan.
Moreover, owing to higher center of gravity of the conventional blade rotor assembly, the blade rotor assembly is prone to be located at higher position adjacent to the hub's top wall, leading to more operational vibration, poorer stability and shorter service life of the radiator fan.
Thus, to overcome the aforementioned problems of the prior art, it would be an advancement if the art to provide an improved structure that can significantly improve the efficacy.
Therefore, the inventor has provided the present invention of practicability after deliberate design and evaluation based on years of experience in the production, development and design of related products.